1. Field of the Invention
The present invention is directed to sampling systems in general, and in particular, to an active sampler for detecting contaminants in liquids, such as water.
2. Description of the Related Art
Systems and apparatuses for sampling are common in the field of water monitoring, including determining the presence of contaminants in natural waterways (e.g., springs, rivers, and creeks), as well as in industrial and municipal discharges.
However, conventional sampling devices usually require the presence of a user at the site to manually take the liquid sample (e.g., in a test tube). The user then analyzes the samples by, for example, introducing chemicals into the sample to detect the presence of a contaminant.
Conventional sampling techniques typically involve taking discrete samples at widely spaced time intervals. Such discrete sampling makes it difficult to easily determine the accumulated concentration of a contaminant over the sampling period. Further, taking discrete samples is costly, particularly if samples need to be taken regularly (e.g., several times a month). The cost and inconvenience is further increased when the sampling of remote locations is desired.
Conventional active samplers, though able to continuously sample, generally require relatively large amounts of energy to pump the liquid through the sampler due to the large pressure differential through the system, thus making them unsuitable for use in remote locations without power. Additionally, these samplers can be bulky and unsuitable for deployment in shallow bodies of liquid or in piping infrastructure.
Accordingly, there is a need for an improved active sampling device for detecting contaminants in liquids.